Pumping unit for refrigerating apparatus



Jan. 30, 1934.- M. c. TERRY 1,945,338-

PUMPING UNIT FOR REFRIGERATING APPARATUS Filed June 13, 1931 lll zum? Ilm l Patented Jan. 30, 1934 UNITED STATES PUMPING UNIT FOR REFRIGERATING APPARATUS Matson C. Terry, Longmeadow, to Westinghouse Electric &

a corporation of Pennsylvania Company,

Mass., assignor Manufacturing Application June 13, 1931. Serial No. 544,264

4 Claims.

This invention relates to refrigerating apparatus, and particularly to a lubricating system for the moving parts of a compression-type apparatus.

The invention has for an object to provide a compression mechanism of the character described which shall have associated therewith an eflicient and noiseless system of lubrication for the working parts of the motor and Compressor.

A further object of the invention is to utilize the suction pressure of the compressor to cause positive circulation of the lubricating fluid of a refrigerating machine to the Working parts of 1| the compression unit.

A still further object of the invention is to secure a positive circulation of the lubricating medium in a refrigerating machine Without the use of an oil pump or other instrumentality having moving parts.

Other objects and advantages of the invention will be readily apparent from the following description of the accompanying drawing, wherein Figure 1 is an end View, partly in section, of a motor-compressor unit, the end plate being removed;

Fig. 2 is an end view of a refrigerating apparatus embodying the invention, with the motor compressor unit shown in section on line II-II of Fig. 1 and including diagrammatically the heat-absorbing and heat-dissipating units of a complete refrigerating system.

Fig. 3 is an enlarged view of the Venturi construction shown in Fig. 1.

erating apparatus and to insure positive lubrication without any mechanical pump or other moving apparatus, the suction of the compressor is utilized. f

In order to so utilize the suction of the connpressor as to entrain oil and lubricate the moving parts of the compressor, the conduit carrying the refrigerating medium, as a gas, from the evaporator back to the compressor is so constructed as to be at least partly submerged in the oil normally maintained at a predetermined approximate level in the compressor casing, the conduit having its outlet directly above the crankshaft of the compressor mechanism.

Inserted in this conduit, which has a Venturi tube construction to impart additional velocity to the gas and to ensure operation, is a small conduit extending down into the oil and having its outlet at the throat of the Venturi tube construction of the refrigerant conduit.

In order to obtain lubrication of the refrig- As the compressor creates a vacuum in the refrigerating conduit and a consequent rapid velocity of the refrigerating gas, the oil will be sucked up through the conduits and will be ejected over the working parts of the compressor and the motor shaft.

The oil is entrained in the refrigerating gas, the lifting force to raise the oil to the refrigerant conduit being obtained from the constant evacuation of the refrigerant conduit by the compressor, while the machine is running, and the entraining effect is caused by the moving gasholding particles of oil thus lifted and carrying the oil along to eject it over the crankshaft to lubricate the compressor and motor bearing.

The oil is returned to the reservoir at the bottom of the casing in the manner shown in the copending application of Frank Conrad and Christian Aalborg, Serial No. 439,408, filed March 27, 1930, for Pump for refrigerating apparatus and assigned to the Westinghouse Electric and Manufacturing Company.

Referring to the drawing for a detailed description of an embodiment of the invention, a compressor 10 is driven bya motor l1, connected 80 by means of a shaft 26 mounted in a support 30.

v--Both the motor and the compressor are enclosed within a fluid-tight casing l2.

The compressed gas is conveyed from the compressor, through a conduit 13, to the condensing coils 14. The liquefied refrigerantl is reduced in pressure in the expansion valve 15 and absorbs heat from the evaporator 16.

The gaseous refrigerant is returned to the compressor casing 12 by means of a conduit 17 having its entrance to the casing at point 18.

The refrigerant is cooled in the condensing coils by means of a fan 9 driven. by cobalt-steel magnets 19 inside the casing 12, `in the manner shown and described in my copending application, Serial No.316,068 led October 30; 1928.

The gas is returned to the compressor casing at point 18 and is carried to the top of the casing by means of conduit 20 of relatively small diameter which is always at least partly submerged in oil 21 maintained in the compressor casing 12, for a purpose hereinafter pointed out.

Inserted in the conduit 20, is a small conduit 22 extending downwardly into the oil and having its upper opening 34 at the throat of the Venturi-tube construction 23 formed in the conduit 20.

The operation of the lubricating means is as follows. Upon rotation of the motor 11, the compressor 10 is actuated, and the pressure in the evaporator 16 is thereby reduced, as well as the pressure in the casing 12. Vaporization of the liquid refrigerant contained .n the evaporator 16 is thereby effected, and heat is absorbed in a manner well understood in the art. The refrigerant vapor thus produced in the evaporator 16, passes through the conduits 1'7 and 20 and is drawn into the casing 12.

-The conduit 20 leading to the position adjacent to the crank shaft 25 as shown and having the conduit 22 inserted therein with its opening at the throat of the nozzle 23, is oi relatively small diameter. Since low pressure caused by the pumping action of the compressor 10 exists in the hermetically sealed casing, gaseous media is drawn through conduit 17 and 20, be-

cause of the slightly higher pressure existing in the evaporator 16. It is obvious that, if a Venturi tube were not placed in the conduit 20 as shown at 23, the pressure at 23 would be slightly higher than the pressure at the opening 24 of the conduit 20 and that, therefore, oil would not flow from the reservoir 21. The Venturi tube 23, however, converts some of the pressure existing in the conduit 20 into velocity whereby the pressure just in back of the throat 23 is lowered. Oil is therefore lifted by suction through the conduit 22 and is sprayed into the conduit 20 where it is entrained by high velocity refrigerating vapor, which carries globules of lubricant with it and elects them through the opening 33 of the conduit-20. The oil level ofthe reservoir 21 is preferably arranged above the throat of the Venturi tube 23 and also above the discharge end of the small conduit 22 whereby a supply of lubricant is ensured for the conduit 22 to maintain it in a primed condition, which condition is necessary for the eiiicient and positive operation of an injector of this type.

The iine spray of oil is ejected from the chamber 24, covered by a screen 33 upon a crankshaft 25 of the compressor which crankshaft is provided with a counterweight 27. Some of the oil drops from the crankshaft 25 and goes back to the oil reservoir 21. The remainder of the oil is carried along the bearing 26 which connects the compressor 10 and the motor by means of a conduit 35 which connectsrwith a groove 31 which extends the length of the bearing 26, thus lubricating it.

The oil which is carried along the bearing 26 is caught by trap 28 and is carried back to the compressor casing 12 through the passage 29 formed in the support 30.

The oil reservoir 21 is nlled so that it will always be at a level to ensure oil being supplied to the conduit 22.

The operation of the lubricating means is noiseless and has no moving parts.

It will be understood from the foregoing description that Il have invented a system for lubricating refrigerating apparatus by using the suction of the compressor to raise the lubricant and providing conduits so arranged as to carry it to the desired places and return it to a reservoir. It will also be understood. that the lubricating system has no moving parts and is, therefore, noiseless and has nothing to wear out or replace.

Although I have shown and described a speciiic embodiment oi my invention, it is understood that it may be used in other types of machines than the lone shown, and that modifications may be made by those skilled in the art without departing from the spirit and scope of the appended claims.

I claim as my invention:

1. In a compression type refrigerator, a compressor having parts requiring lubrication, a casing for the compressor, a lubricant reservoir formed by the casing, means providing a suction passage for the compressor including a conduit and an injector for supplying lubricant from the reservoir to the conduit and motivated by gaseous media passing therethrough, said conduit being arrsnged to supply lubricant to said compressor par 2. In a` compression type refrigerator, a compressor having parts requiring lubrication, a casing for the compressor, a lubricant reservoir formed by the casing, means providing a suction passage for the compressor including a conduit having a discharge end arranged above said parts, and an injector motivated by gaseous media passing through the conduit for supplying lubricant from the reservoir to the latter for passage to the discharge end of the conduit so as to be supplied to said parts.

3. In a compression type refrigerator, a compressor having parts requiring lubrication, a casing for the compressor, a lubricant reservoir formed by the casing, means providing a suction passage for the compressor including a conduit, and an injector for supplying lubricant to the conduit and motivated by gaseous media passing therethrough, said conduit being arranged to supply lubricant to said compressor parts, said injector including a Venturi passage divided by the conduit, and a pipe extending into the conduit and having its discharge end arranged at the throat of the passage, means providing for submergence below -the lubricant level of the inlet end of said pipe and at least the portion of the conduit containing the throat of said Venturi passage and the inlet end of said pipe.

4. In a compression type refrigerator, a compressor having parts requiring lubrication, means providing a suction passage forv the compressor a conduit extending into it, said chamber having its lower portion providing a lubricant reservoir, an injector for supplying lubricant from the reservoir to the conduit and motivated by gaseous media passing through the latter, the discharge end of said conduit being arranged to discharge lubricant into said parts.

, MATSON C. TERRY.

vincluding a casing enclosing the compressor and l 

